Electrode mounting



Nov. 3, 1936. w. PERscH ELECTRODE MOUNTING Filed Aug. 20, 1935 Inventor. Wilhelm persch,

'b g At omweg. AMI

Patented Nov. 3, 1936 PATENT OFFICE ELECTRODE MOUNTING Wilhelm Persch, Berlin, Germany, asslgnor to General Electric Company, a corporation of New York Application August 2o, 1935, serial No. 37,009 In Germany March 15, 1935 My invention relates to an electrode mounting for electric discharge devices, and more particularly to an improved stem tube for such a mounting.

An object of this invention is to provide a mounting which permits shortening the electrode supports and consequently increasing the rigidity of the electrode structure.

A further object is to provide an assembly fulfilling the above conditions which is characterized by simplicity and economy of construction.

The novel features which I consider to be characteristic of my invention will be pointed out with particularity in the appended claims. My invention itself may best be understood by reference to the following specification taken in connection with the drawing in which Fig. 1 represents a partial section illustrating an electrode assembly embodying the principles of my invention, while Fig. 2 represents a detailed section taken in a plane degrees displaced from that of Fig. 1.

Referring more particularly to Fig. 1, I have shown a fragmentary section of a discharge tube construction particularly adapted for use as a positive column lamp or similar luminous discharge device. The enclosing envelope is shown only in part, the anode portion of the tube being broken away. It will be seen that the stem tube, designated as a whole by the numeral I, comprises a glass element of essentially circular cross-section and provided at its base with a ared portion 2. 'I'his flare is sealed into an opening in the end of the enclosing envelope 3 and forms a vacuum-tight closurefor the same.

Intermediate the ends of the stem tube I and adjacent its center I provide a press 4 formed by attened or compressing the walls of the tube in a region adjacent the center of the tube. This method of production is especially advantageous since a number of lead-in conductors 5, 6 and 1 may be alined in parallelism in the bore of the tube and imbedded in the press at a single operation. As illustrated, conductors 5 and 6 run lengthwise of the stem tube I and are arranged to supply heating current to a lamentary coil 8 arranged within the envelope enclosure. The conductors 1 alfords a means of fixing the potential of the auxiliary electrode 9. This latter element is shown as comprising a cylinder alternatively consisting of metal or graphite adapted to serve as a starting electrode or a heat shielding means for the cathode or jointly for such purposes. In case the tube illustrated is of the symmetrical type used on alternating current circuits, the auxiliary electrode may also act as an anode member to receive the discharge current during that portion of the voltage cycle in, which the electrode parts with which it is associated become positive. 6 Extending above the press 4 and comprising a prolongation of the body of the stem tube, I provide a free tube end I0 opening into the interior of the enclosing envelope. For additionally supporting the electrode 9 and the block of 10 electron-emissive material II which is disposed axially of the cathode heating coil I provide rigid supporting elements I2 and I3 which may be mounted externally of the stem tube I adjacent its free end. These supports are held in place l5 by clamping rings I4 and I5 which t snugly upon the external surface of the stem tube cylinder.

By utilizing in this manner the portion of the stem tube which projects above the press it will 2o be seen that I have shortened the necessary length of the electrode-supporting elements and correspondingly increased their inherent rigidity. Additionally, the Weight of the electrode structure is so distributed that little or no strainis 25 imposed at any time upon the glass to metal seal constituting the press. At the same time the uniform dimensions of a stem tube of the type employed are such as to facilitate its introduction into an envelope having a relatively small open- 30 ing in the end thereof.

While I have shown a particular embodiment of my invention, it will of course be understood that I do not wish to be limited thereto since many modifications in the structure may be 35 made, and I contemplate by the appended claims to cover all such modifications as fall Within the true spirit and scope of my invention.

What I claim as new and desire to secure by Letters Patent of the United States is:

1. A stem tube for an electrode-containing vessel, which tube comprises a hollow cylinder having a sealing are adjacent one end thereof, a press adjacent the center of the cylinder constituting a flattened portion of the cylinder walls, and an open end portion of the cylinder remote from said flare and press.

2. An electrode mounting comprising a stem tube of insulating material having a sealing flare adjacent one end thereof, a flat press adjacent the center of said tube constituting a flattened portion of the walls thereof, lead-in conductors passing through said tube and press, and electrode supporting means mounted externally of 55 said tube at the end thereof remote from said nare.

3. An electrode mounting comprising a. cylindrical glass stem tube, a fiat press consisting of a compressed portion of the walls of said tube intermediate between the ends thereof, alined conductors sealed into said press and passing axially through said tube, and electrode supporting-means mounted externally of said tube, said 10 means comprising one or more clamping rings. 4. In an electric discharge device. an enclosing envelope, electrode members therein, a glass stem tube having a flare sealed into a wall of said envelope and a free end opening toward the interior of said envelope, a press in said tube intermediate said are and said free end and constituting a attened portion of the walls of the tube, lead-in conductors for said electrodes sealed into said press, and electrode supporting means mounted exteriorly of said tube at the free end thereof.

l WILEEILM PERSCH. 

